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Skin: Sentinel lymph node biopsy indication

Free question published 08 August 2026

SkinSentinel lymph node biopsy indication

A 44-year-old woman has a melanoma excised from her calf. Histology shows a Breslow thickness of 0.9 mm with ulceration and a mitotic index of 3 per mm2. There is no clinical or radiological evidence of nodal disease. She asks whether she needs any further nodal assessment. What is the most appropriate management?

  1. ADo not offer SLNB, as Breslow thickness is below 1.0 mm
  2. BConsider SLNB because of the Breslow thickness with ulceration and mitotic index
  3. CProceed directly to completion lymph node dissection of the groin without sentinel lymph node biopsy staging
  4. DOffer therapeutic groin radiotherapy
  5. EArrange PET-CT instead of any nodal sampling

Why B is correct

NICE NG14 advises considering SLNB for melanoma with a Breslow thickness of 0.8 mm to 1.0 mm and at least one of ulceration, lymphovascular invasion, or a mitotic index of 2 or more. This 0.9 mm tumour has both ulceration and a mitotic index of 3, so SLNB should be considered for staging and prognostic information.

And why the others are not

  • AIncorrect: although thickness is under 1.0 mm, the 0.8-1.0 mm band with adverse features (ulceration, mitotic index of 2 or more) is exactly the group for whom SLNB should be considered.
  • CIncorrect: completion lymph node dissection is not a staging procedure and is not indicated without a positive sentinel node; MSLT-II showed no survival benefit even then.
  • DIncorrect: there is no nodal disease, so therapeutic nodal radiotherapy has no role here.
  • EIncorrect: imaging such as PET-CT is not offered before SLNB unless nodal or distant metastases are suspected, and it does not replace SLNB for microscopic nodal staging.

Source NICE NG14 - Melanoma: assessment and management — National Institute for Health and Care Excellence. Melanoma: assessment and management. NICE guideline NG14. Published 29 July 2015, updated 2022.

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